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Search Publications

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Displaying 51 - 75 of 1316

Resistance Heating of the Gasket in a Gem-Anvil High Pressure Cell

October 12, 2021
Author(s)
N M. Balzaretti, E J. Gonzalez, Gasper J. Piermarini, T Russell
The design and fabrication of a modified gem-anvil high pressure cell capable of statically heating gasketed samples to temperatures in the range of 1100 degrees C at pressures up to 4.0 Gpa is described. The high temperatures were achieved by resistance

Secondary Phase Evolution in Silicon Nitride During Creep and Heat Treatment

October 12, 2021
Author(s)
F Lofaj, H Gu, A Okada, Sheldon M. Wiederhorn, H Kawamoto
The microstructure of a ytterbia- and yttria-containing grade of silicon nitride, SN 88, was investigated after it had been annealed in nitrogen, in air and crept in air. We were particularly interested in phase transformation within the secondary silicate

Self-Assembled Multiferroic Nanostructures in CoFe 2 O 4- PbTiO 3 System

October 12, 2021
Author(s)
Jiying Li, Igor Levin, Julia Slutsker, Virgil Provenzano, Peter K. Schenck, J.H. Yang, Alexander L. Roytburd
The effect of substrate orientation of the morphologies of epitaxial self-assembled nanostructures was demonstrated using newly synthesized multiferroic 0.67PbTiO3-0.33CoFe2O4 nanocomposite thin films. The two-phase nanostructures were grown on single

Shape of Hollow Dislocation Cores: Elastic and Anisotropic Surface Energy Effects

October 12, 2021
Author(s)
David J. Srolovitz, N Sridhar, J P. Hirth, John W. Cahn
Evidence for the existence of hollow core dislocations has existed for nearly forty years. Such hollow cores are often found in growth spirals associated with screw dislocations. Examples of this type of morphology may be found in silicon carbide, copper

Simulating Thermal Response of EB-PVD Thermal Barrier Coating Microstructures

October 12, 2021
Author(s)
M Bartsch, U Schulz, J M. Dorvaux, O Lavigne, Lin-Sien H. Lum, Stephen A. Langer
As ceramic thermal barrier coatings (TBC) are used in more critical applications in advanced engines, knowing basic physiproperties of TBC's is essential for design and reliability assessment. In particular, knowledge of thermal conductivity is cruciin

Simulation of a Single Asperity Impacts at Head-Disk Interface

October 12, 2021
Author(s)
Tze J. Chuang, Stephen M. Hsu
During the track accessing mode of a hard disk drive, the flying height of the slider over the disk surface becomes smaller and smaller as the demand in data storage a real density increases. As a result, the propensity of glide avalanche is bound to

SiO 2 /Si 3 N 4 /A1 2 O 3 Stacks on Silicon for Scaled-Down Memory Devices: Effects of Interfaces and Thermal Annealing

October 12, 2021
Author(s)
M Lisiansky, A Heiman, M Kovler, Y Roizin, Igor Levin, A Gladkikh, M Oksman, R Edrei, A A. Hofman, Y Shnieder, T Claasen
Effects of interfaces and thermal annealing on the electrical performance of the SiO2/Si3N4/A12O3 (ONA) stacks in non-volatile memory devices were investigated. Structural and electrical characterization demonstrated the principal role of the Si3N4/A12O3

Solidus Phase Relationships in the AO-Al 2 O 3 -Nb 2 O 5 (A = Ca, Sr) Systems

October 12, 2021
Author(s)
Julia Y. Chan, Wilma Feb-Ayala, L D. Rotter, Igor Levin, Richard G. Geyer
Dielectric ceramics for wireless communications exhibiting modest permittivity, high quality factor (Q), and near-zero temperature coefficient are needed for high frequency, high power applications. Efforts are in progress to replace Ta 2O 5-based ceramics

Stoichiometry and Phase Composition of MOCVD Barium Titanate Films

October 12, 2021
Author(s)
Charles E. Bouldin, Joseph Woicik, Bruce Ravel, Debra Kaiser, Mark D. Vaudin
X-ray absorption fine structure (XAFS), x-ray diffraction (XRD) and x-ray fluorescence (XRF) have been used to study the stoichiometry and phase composition of thin (approximately equal to} 1 micron) films deposited on MgO substrates. Deposition

Strength Evaluation on a Composite Marine Propeller Blade

October 12, 2021
Author(s)
H J. Lin, J J. Lin, Tze-Jer Chuang
The strength of a composite propeller blade is evaluated by performing a nonlinear hydro-elastic analysis. The finite element method, lifting surface theory, least square method, equilibrium equation and Hashin failure criteria are employed for the

Structure and Crystal Chemistry of M 0.5 Ta 0.5 B (M = Ti, Zr, and Hf)

October 12, 2021
Author(s)
I Talmy, J Zaykoski, J A. Kudak, Winnie Wong-Ng
During the development of refractory composites (cermets) combining MB2 (M=Ti, Zr, or Hf) ceramics and Ta metal, three new phases of compositions M0.5Ta0.5B were discovered. Preliminary determination of lattice parameters using x-ray powder diffraction

Subsolidus Phase Relationships in the AO-AI 2 O 3 -Nb 2 O 5 (A=Ca, Sr) Systems

October 12, 2021
Author(s)
Julia Y. Chan, Wilma Feb-Ayala, J. M. Loezos, L D. Rotter, Lyle E. Levine, Richard G. Geyer
Dielectric ceramics for wireless communications exhibiting modest permittivity, high quality factor (Q), and near-zero temperature coefficient are needed for high-frequency, high power applications. Efforts are in progress to replace Ta 2O 5-based ceramics

Surface Energy Anisotropy of SrTiO 3 at 1400 C in Air

October 12, 2021
Author(s)
T Sano, D M. Saylor, G S. Rohrer
Geometric and crystallographic measurements of grain boundary thermal grooves and surface faceting behavior as a function of orientation have been used to determine the surface energy anisotropy of SrTiO 3 at 1400 C in air. Under these conditions, thermal

Surface Morphology Dependent Magnetic Thin Film Growth: Fe on GaN(0001)

October 12, 2021
Author(s)
P Ryan, R A. Rosenberg, D J. Keavney, J W. Freeland, Joseph Woicik
Iron deposition on ordered and disordered GaN (0001) surfaces result in dramatically different magnetic over-layer characteristics. On the ordered surface, nitrogen rapidly desorbs upon Fe deposition and a magnetically disordered film is produced

Synchrotron Based Surface Science to Probe Polymeric Interfacial Regions

October 12, 2021
Author(s)
Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, Daniel A. Fischer
Synchrotron based X-ray absorption spectroscopy was utilized to probe the chemistry and structure of polymers in interfacial regions, including the interfacial regions, including the interfacial composition of filled epoxy composites, and the surface

Tailoring the High-K Gate Dielectric/Sillicon Interface for CMOS Applications

October 12, 2021
Author(s)
Y S. Lin, R Puthenkovilakam, J P. Chang, C P. Bouldin, Igor Levin, Nhan Van Nguyen, Y Sun, P Pianetta, T Conard, W Vandervorst, V Venturo, S Selbrede
The interfacial properties, thermal stabilities, and the electrical characteristics of ZrO 2/ Si and ZrO 2/SiO 2/Si were investigated and the interfacial layer of as-deposited ZrO 2 on silicon is likely to be ZrSi xO y. The ZrO 2/ZrSi xO y/Si is

The Crystal Chemistry of L-Ta 2 O 5 and Related Structures

October 12, 2021
Author(s)
I E. Grey, W G. Mumme, Robert S. Roth
Single crystals of a new form of L-Ta2O5 with a 19 x b superstructure have been synthesised by flux growth. The phase has C-centred monoclinic symmetry with a = 6.199(1) , b = 69.55(1) (= 19 x 3.66 ), c = 3.880 (1) . The structure was refined in space
Displaying 51 - 75 of 1316